30
layers of the funnel show
only ost 37 and sp??5 in the deenest
_
layer,
Buried Organic Layers
The organic matter in buried hocizons may become important
in the vertical distribution of radilonuclides in the snils.
No
detectable gamma-emitters were found in buried horizons during
the period 1958-1961.
In September 1963 a core was taken through
a buried horizon at 14 inches in old soil.
Radioautographs of
sections of the core show that a small amount of radioactivity
has accumulated in the buried horizons
The diffuse distribution
‘
of the radioactivity in this case indicates that there is adsorption of the radionuclides from solution as water percolates
through the soils, although the possibility of translocation by
plants cannot be ruled out.
csi 3? and naturally occurring ,0
were the only radionuclides present in the buried horizon.
The accumulation of es! 37 in the buried horizons is of particular significance in terms of plant-soil relationships,
because a proliferation of roots is often found in the buried
13
horizons and és??’
is the principal fallout radionuclide taken
up by atoll plants.
Roots
Roots, which contain est3? and sr?°,
in most instances have
higher levels of radioactivity than the surrounding soil except
near the soil surface (Fig. 12).
The influence of poplar roots
on redistribution in a continental soil has been well demonstrated